Extruding and improving of lead alloys



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Fatentebl June as, teas.

STATES earner crazies.

REGINALD SCOTT JDJEAN AND WILLIAM EWAR'I HUDSON, OF OAK PARK, ILLINQIS, AS-

SIGNQRS TO WESTERN ELECTRIC COMPANY, INCORPORATED, 015 NEW YORK, N. Y

A CORPORATION @115 NEW YORK.

EXTRUDTNG AND IMPROVING 01F LEAD ALLOYS.

l\To Drawing.

An object of this invention is to provide a process for extruding lead alloys so that the extruded article may be afterwards improved.

A. further object of this invention is to provide a process for improving extruded lead articles after extrusion has taken place.

This process is described as applying to lead-antimony cable sheath, but it is to be understood that the same process may be applied in extruding and improving articles made of other lead alloys such as lead-tin alloys, etc.

According to this process the proper proportions of lead and antimony are cast into the form of a slug or ingot. This ingot is then heated for a period of time, depending upon the percentage of antimony present and the temperature at which the heating apparatus is maintained. When this period of time has elapsed the ingot is placed in an extruding press and extruded in the form of cable sheath, substantially as outlined in the co-pending application of R. S. Dean and W. E. Hudson, Serial No. 690,717 filed February 5, 1924. Immediately upon emanation from the die, the hot sheath is quenched. The sheath is then coiled onto the reels in the ordinary manner and allowed to age at room temperature.

As an alternative the ingot may be cast in the extruding press and-heated while in the press,-the extrusion and quenching then being carried on as above. This method is not so desirable, on account of the time required for heating, as during the heating the extruding press would have to remain idle. Y 1

In order to get the maximum amount of hardness, as the improved quality, accord.- ing to this method, an alloy of slightly less than 2 antimony is used with pure lead. The time of heating is 72 hours, and temperature 240 C. The quenching bath may be ordinary running water at approximately or slightly below room temperature. The time required for testing out the cable, sealing the ends, etc. in practice is found to give sufiicient aging to obtain substantially the hardness required. (For a full description of this hardening method refer- Application filed February 5, 192%. Serial No. 690,718.

fence is made to our co-pending application,

Serial No. 690,716 filed February 5, 1924.)

As described in the copending application just cited, the method of improving the lead alloys consist generally in heating an alloy composed of lead-antimony, lead-tin or other materials until the material alloyed with the lead is in solid solution therein, quenching the heated alloy to a temperature below the temperature of recrystallization of the alloy, and aging the quenched alloy at room temperatur'e.

l yhen employing underground cable, especially underground cable of the larger sizes, it is impossible to conveniently handle sheath employed in such cases may be thinner than. the sheath which'has heretofore been used, but on account of the necessity of preserving its flexible character it cannot be made as thin as the required tensile strength would seem to indicate.

The hardness of the cable sheath may be reduced in various Ways, such as decreasing the percentage of antimony, decreasing the time or temperature of heating, or by allowing the alloy to partly cool before quenchlng. A specific manner in which the process may be varied as indicated is more fully explained in our co-pending application'referred to above.

By using hardened lead antimony alloy for the making of cable sheath, the thickness of the sheath may be materially reduced, resultlng in a saving in material and still have much greater tensile strength, hardness, and resistance to abrasion than has away with the messenger wire and rings which are now commonly employed to sup- .port this type of cable.

If it is desired to keep the cable sheath or other article soft for a period of time, after quenching, said article may be put into cold' storage, i. e., stored in temperatures of 0 C. or lower. This lower temperature appreciably retards the age-hardening. This may be of considerable advantage in working with large objects, for example, the "larger sizes of cable sheath.

What is claimed is:

1. A process for producing an improved lead cable sheath, which consists in alloying antimony with lead, reducing-the resulting alloy to a solid solution to facilitate its extrusion, extruding said alloy into cable sheath, quenching said extruded alloy while in the solid state to produce a supersaturated solid solution, and causing said alloy to assume a more stable state.

r 2. A method for roducing an improved lead cable. sheath, w ich consists in alloying matter with lead, reducing the alloy to a substantially homogeneous solid solution to facilitate its extrusion, forming the resulting alloy into cable sheath, quenching said formed alloy to produce a supersaturated solid solution, and causing said alloy to assume a more stable state.

3. A method for roducing an improved lead cable sheath, which consists in alloying matter with lead, reducing the alloy to a solid solution to facilitate its extrusion, forming said alloy into cable sheath by extrusion, quenching said extruded alloy while in the solid state to produce a supersaturated solid solution, and causing said supersaturated solid solution to gradually assume a substantially stable state.

4. A process for extruding and improving lead alloys, which consists in castmg the alloy into the form of an ingot, heating said alloy ingot until a substantially homogeneous solid solution is formed, ,placin said ingot in an extruding press, extru ing said ingot, quenching the extruded article to a temperature below 100 0., and aging.

5. A process for improved lead-antimony cable sheath, which consists in casting the alloy in requisite pro ortions in the form of an ingot, heating said ingot for 7 2 hours at a temperature below the fusin temperature to produce a solid solution w ich contains substantiall all of the antimony present in the alloy, p acing said ingot in an extruding press, extruding said ingot into cable sheath, quenching said sheath, and aging.

6. A process for improved lead-antimony cable sheath, which consists in casting the alloy in requisite proportions in the form of an ingot, heating said ingot for 72 hours at a temperature of 240 (5., to produce a solid solution which contains substantially all of the antimony present in the alloy, placing ermite said ingot in an extruding press, extrudin said ingot into cable sheath, quenching saivf sheath, and aging.

7. A process for producing improved leadantimony cable sheath, which consists in casting the alloy in requisite proportions in the form of an ingot, heating said ingot for 7 2 hours at a temperature of 240 C. to produce a solid solution which contains sub stantially all of the antimony present in the alloy, placing said ingot in an extruding press, extruding said ingot into cable sheath. quenching to room temperature, and aging.

8. A process for producing improved leadantimony cable sheath, which consists in casting the alloy in requisite proportions in the form of an ingot, heating said ingot for 7 2 hours at a temperature of 240 C. to produce a solid solution which contains substantiall all of the antimony present in the alloy, placing said ingot in an extruding press, extruding said ingot into cable sheath,

quenching tq room temperature, and aging at room tem 'erature.

9. A process for producing improved lead cable sheath, which consists in alloying with lead not less than 1% and not more than 2.5% antimony, casting the resultin alloy into the form of an ingot, heating sai ingot at a temperature below the fusing temperature to reduce the alloy to a substantially homogeneous solid solution, extruding said ingot into cable sheath, quenching, and aging.

10. A process for producing improved lead cable sheath, which consists inalloying with lead not more than 2.5% antimony, but more antimony than is soluble in solid lead at room temperature, casting the resulting alloy into the form of an ingot, heating said ingot at a temperature slightly below the fusion temperature to roduce asubstantially homogeneous solid so ution, extruding said ingot into cable sheath, quenching, and aging.

11. A process for improving lead alloy articles, which consists in casting the alloy in the form of an ingot, heating said ingot at a temperature below the fusion temperature until a solid solution is formed, said solid solution containing substantially all of the material alloyed with the lead, extruding said ingot into the form desired, quenching said extruded article, and aging.

12. A process for improving lead-antimony cable sheath, which consists in heating a cast ingot at a temperature below the fusion temperature until a solid solution is formed, said solid solution containing substantially all of the antimony present in the alloy, extruding said ingot in the form of a cable sheath, quenching said sheath, and aging.

13. A process for improving lead-antimony cable sheath, which consists in casting newness nn ingot, heating saidl ingot at n tempere tore below the tusion tem emture until at solid solution is ton-mod sold solid solution containing substantial all of the entimony present in the alloy, p swing said ingot into on exttnsion press extruding said ingot into a cable sheath, quenching Sfilid cable sheath,

and aging snitt enhte sheath nt TUQFH tempera tune.

In Witness wheremf We hereunto subscribe Z1 0111K names this 22nd day of Jnnunty A. 111

REGINALD SCQTT DEAN WILLIAM EWART HUDSQN, 

